If you have 2.2 x 10^24 molecules of o2 at stp how many liters of o2 do you have

According  to  Avogadro  law  the  volume  and  moles  of  a  gas  is  directly  proportional  at constant  pressure  and  temperature.
Number  of  moles  is  therefore  number  of  molecules/Avogadro  constant(6.02 x10^23)
(2.2 x10^24)/(6.02  x10^23) =3.654moles
Every moles  of  an  ideal  gas  occupy  22.4L  at  S.T.P
therefore  volume  is
3.654  x22.4L=81.85L